Establishment and Evaluation of Leak Collection System Analysis Method Using CFD Analysis

Suppose a small amount of leakage exceeds the limit of the operating conditions of a nuclear power plant. In that case, losses due to the nuclear power plant shutdown may occur, or accidents due to leakage may occur. Consequently, there has been a need to develop a system capable of quickly detecting even small amounts of leakage, and research has been conducted to address this need. To develop such a system, it is necessary to understand the thermal-hydraulic characteristics of the system. This study established a CFD-based evaluation process for evaluating leak detection systems. A numerical analysis model was used to simulate leakage, and a two-step CFD analysis was performed to assess its applicability. In the first step, a study of the leakage behavior in the insulation material was conducted, and the effect of the gap between the pipe insulation material and the outer cover was evaluated. In the second step, the collection loop was analyzed using the results of the leakage behavior analysis in the insulation as an input condition. The results of this study were used to construct the collection loop experimental device and will help in understanding the heat flow characteristics in the collection loop.